Mask structure and FCVA apparatus

Abstract

Embodiments of the present disclosure provide a mask structure and a filtered cathodic vacuum arc (FCVA) apparatus. The mask structure is configured to prepare protrusions on a carrying surface of an electrostatic chuck and includes a main mask plate and a side mask plate that are made of a conductive metal. The main mask plate is configured to form a patterned film layer corresponding to the protrusions on the carrying surface of the electrostatic chuck. The side mask is configured to cover a side surface of the electrostatic chuck to avoid forming a film layer on the side surface. The mask structure can be electrically conductive. The mask structure may prevent the side surface of the electrostatic chuck from being coated when the protrusions are prepared on the carrying surface of the electrostatic chuck. Thus, the mask structure may be applied to an FCVA process.

What is claimed is: 
     
       1. A mask structure configured to prepare protrusions on a carrying surface of an electrostatic chuck, comprising:
 a main mask plate made of a conductive metal and configured to form a patterned film layer corresponding to the protrusions on the carrying surface of the electrostatic chuck; 
 a side mask plate made of the conductive metal and configured to shield a side surface of the electrostatic chuck to avoid forming a film layer on the side surface; 
 a float lock assembly configured to apply a unidirectional force toward the carrying surface of the electrostatic chuck on the main mask plate to fix the main mask plate to the carrying surface, correspondingly, a center through hole being arranged in the main mask plate and a main body portion of the electrostatic chuck; and 
 a center fastening bolt configured to be mounted in the center through hole to fix the main mask plate to the main body portion of the electrostatic chuck. 
 
     
     
       2. The mask structure according to  claim 1 , wherein the side mask plate is configured to be arranged around the side surface of the main body portion of the electrostatic chuck and cover an edge portion of the electrostatic chuck protruding from the side surface of the main body portion. 
     
     
       3. The mask structure according to  claim 2 , wherein the side mask plate includes:
 a first body arranged on a front surface of the edge portion of the electrostatic chuck; 
 a second body arranged on a back surface of the edge portion of the electrostatic chuck; 
 a third body arranged around a side surface of the edge portion of the electrostatic chuck and electrically contacting with the first body and the second body; and 
 a fastener screw configured to fixedly connect the first body and the second body to the edge portion of the electrostatic chuck. 
 
     
     
       4. The mask structure according to  claim 3 , wherein a buffer is arranged between the first body and the edge portion of the electrostatic chuck and/or between the second body and the edge portion of the electrostatic chuck. 
     
     
       5. The mask structure according to  claim 1 , further comprising:
 a ring-shaped shield plate arranged on a front surface of the main mask plate, and an inner edge of the ring-shaped shield plate extending to an inner side of an edge of the main mask plate. 
 
     
     
       6. The mask structure according to  claim 1 , wherein:
 a ring-shaped recess penetrating to a front surface of the side mask plate is arranged on an inner surface of the side mask plate; and 
 an edge portion of the main mask plate is located in the ring-shaped recess. 
 
     
     
       7. The mask structure according to  claim 1 , further comprising:
 a conductive elastic member electrically connecting the main mask plate and the side mask plate. 
 
     
     
       8. The mask structure according to  claim 1 , wherein the float lock assembly includes:
 a lock nut including a nut body and a ring-shaped flange arranged at one end of the nut body, the ring-shaped flange protruding from a peripheral surface of the nut body, a threaded hole being arranged at an end surface of the other end of the nut body; 
 a first through hole penetrating along a thickness direction of the main mask plate, correspondingly; 
 a second through hole being arranged in a main body portion of the electrostatic chuck and penetrating along an opposite direction of the first through hole, the nut body penetrating the first through hole and the second through hole, and the ring-shaped flange being stacked on a front surface of the main mask plate; 
 a screw passing through penetrating the second through hole and cooperating with the threaded hole, a head of the screw being located on a back surface of the main body portion of the electrostatic chuck; and 
 an elastic member being arranged between the head of the screw and the back surface of the main body portion of the electrostatic chuck. 
 
     
     
       9. The mask structure according to  claim 8 , wherein the elastic member includes an elastic sheet or a compression spring. 
     
     
       10. The mask structure according to  claim 9 , wherein the elastic sheet includes:
 a ring-shaped sheet sleeved on the screw and is stacked on the head of the screw; and 
 a plurality of pressing claws arranged on the back surface of the main body portion of the electrostatic chuck. 
 
     
     
       11. The mask structure according to  claim 8 , wherein a tightening torque of the screw ranges from 0.1 N·m to 0.4 N·m. 
     
     
       12. The mask structure according to  claim 8 , wherein a radial gap exists between the screw and the first through hole. 
     
     
       13. The mask structure according to  claim 1 , wherein one or a plurality of float lock assemblies are included, and the plurality of float lock assemblies are distributed at different positions of the main mask plate. 
     
     
       14. The mask structure according to  claim 1 , wherein:
 a plurality of process holes are arranged in the main mask plate in a one-to-one correspondence with the protrusions; and 
 a rib structure is arranged in an area other than an area where the process holes are located on a front surface of the main mask plate and configured to increase strength and flatness of the main mask plate. 
 
     
     
       15. The mask structure according to  claim 14 , wherein:
 the rib structure includes a ring-shaped rib using a center of the main mask plate as a center of a circle or a plurality of ring-shaped ribs with different radii; and 
 a plurality of radial ribs are arranged between two adjacent ring-shaped ribs and distributed along a circumferential direction of the ring-shaped ribs. 
 
     
     
       16. The mask structure according to  claim 14 , wherein:
 a thickness of the rib structure is greater than or equal to 1 mm; 
 a sum of thicknesses of the rib structure and the main mask plate is smaller than or equal to 5 mm; 
 a thickness of the main mask plate is smaller than or equal to 1.5 mm; and 
 a distance between the rib structure and an edge of any one of the process holes is greater than or equal to 2 mm. 
 
     
     
       17. The mask structure according to  claim 14 , further comprising:
 a hollow portion arranged at a center area of the main mask plate and configured to form a conductive film on the carrying surface of the electrostatic chuck. 
 
     
     
       18. The mask structure according to  claim 17 , wherein the hollow portion includes:
 an arc-shaped hollow portion, a center of the arc-shaped hollow portion coinciding with the center of the main mask plate; and 
 at least three stripe hollow portions symmetrically arranged about the center of the arc-shaped hollow portion, an end of each of the strip hollow portions being connected to the arc-shaped hollow portion, and another end extending along a radial direction of the arc-shaped hollow portion. 
 
     
     
       19. The mask structure according to  claim 1 , wherein the thermal expansion coefficient of the conductive metal is same as a thermal expansion coefficient of the electrostatic chuck. 
     
     
       20. An FCVA apparatus comprising:
 a chamber; 
 a graphite target arranged in the chamber; 
 an electrostatic chuck arranged in the chamber; 
 a mask structure arranged in the chamber and including:
 a main mask plate made of a conductive metal and configured to form a patterned film layer corresponding to the protrusions on the carrying surface of the electrostatic chuck; 
 a side mask plate made of the conductive metal and configured to shield a side surface of the electrostatic chuck to avoid forming a film layer on the side surface; 
 a float lock assembly configured to apply a unidirectional force toward the carrying surface of the electrostatic chuck on the main mask plate to fix the main mask plate to the carrying surface, correspondingly, a center through hole being arranged in the main mask plate and a main body portion of the electrostatic chuck; and 
 a center fastening bolt configured to be mounted in the center through hole to fix the main mask plate to the main body portion of the electrostatic chuck; and 
 
 a power source configured to cause the graphite target to generate carbon plasma through an effect of an arc and deposit a film layer to form protrusions on a carrying surface of the electrostatic chuck through the mask structure.